1. Field of the Invention:
The present invention relates to the field of ultrasonic scanners, and in particular, to drive assemblies which permit an ultrasonic transducer to scan a portion of the body.
2. Art Background
Within the past decade, the use of ultrasound for medical diagnostic purposes has found wide application. Unlike prior methods such as x-ray, surgery or the like, ultrasonic energy as used in medical diagnostics is considered safe. Ultrasonic scanning is frequently used to obtain pictorial cross-sections of the body, measuring th peformance of the heart and blood flow and for identifying tumors, cysts, and other abnormalities. In addition, ultrasonic scanning has particular application to the examination of pregnant women and infants. In the field of obstetrics, ultrasonic scanning has almost completely supplanted older methods of visualizing the uterus.
A variety of ultrasonic scanning systems have been developed which include various mechanisms in order to oscillate an ultrasonic transducer in order to pemit the scanning of a section of the body. See for example, U.S. Pat. Nos. 4,215,585, 4,130,021 and 4,120,291. However, prior art transducer drive assemblies typically include pin and slot coupling arrangements for oscillating a transducer about a given axis. The pin in slot mechanical coupling invariably produces shimmey problems which reduce the accuracy of the scanning systems' ability to position an ultrasonic transducer.
As will be described, the present invention provides an ultrasonic transducer drive assembly which virtually eliminates mechanical play and inaccuracies in the drive mechanism. The present invention provides a direct, cost efficient, and highly reliable transducer drive assembly.